Tenant shall be held responsible for water damage caused by overflowing toilets and/or drains.Take no action which would cause a cancellation or increase in Landlord’s fire or liability insurance.Obey all environmental laws and keep no toxic, inflammable or dangerous substances on the Premises.Prevent the accumulation or buildup of mold or mildew throughout the Premises by notifying Landlord immediately if any evidence of water leak or excessive moisture, mold or mildew appears.

Too much humidity and moisture for the pressure sensitive glue on the back of the tile; too easy for glue to fail and don't even think about adding a glue to help it stick.

@Bryan Devitt The attic is sort-of finished and home inspector thinks there is no good air circulation and moisture which causes mold to form.

It does not tolerate moisture and swells up at the seams instantly if exposed to it. 

Often adding a downspout extension to direct the water from the gutters away from the house will help and is easy to do.For the moisture, they should do whatever they can to dry it out quickly. 

I would fill it just so you don't have moisture seeping in and move on.

Also remember that cement wicks moisture and cold into the new living space. 

He mentioned rebuilding the wall under the window and shoring it up really well with 2x4's and then making forms for a concrete fill in, making sure to put a water barrier, such as red guard on the old adobe surrounding, to avoid moisture from the concrete, dissolving the adobe blocks inside the Plaster walls.  

Sealing the crawlspace would be ideal, but it's not really necessary unless you are having moisture issues. 

They found very high levels of moisture (even in the walls that were recently remediated).